L9: Chaining & Differential Reinforcement

behaviour chains

a sequence of discriminative stimuli (S^D) and responses (R) which each..

• produces a S^D for the next response

• each S^D in a behaviour chain is a cue for the next response

example of a chain

S^D₁ + R₁ + S^D₂ + R₂ + S^D₃ + R₃ …. → S⁺

shaping steps

reinforcement of closer and closer approximations

fading steps

reinforcing the final described responses in the presence of closer and closer approximations

chaining steps

reinforcing more and more of the specific stimuli response

3 chaining methods

1. total task presentation

2. backward chaining

3. forward changing

total task presentation

• attempt all steps at once and continue until mastered. Reinforcement is provided upon completed last step

backward chaining

last step is taught first, and then next to last is taught, etc

forward chaining

initial step is first, then second, etc

task analysis

process of breaking a task down into smaller steps to facilitate learning

differential reinforcement of low rates (DRL)

reinforcing only low rates of responding

types of DRL’s

• limited response DRL

• spaced-responding DRL

limited response DRL

max number of allowed responses during an interval

spaced responding DRL

behaviour does not occur during interval, occurs after interval, and behaviour happens for reinforcement

differential reinforcement of zero responding (DRO)

reinforcer presented only if response does not occur within an interval

what happens if a response occurs in interval for (DRO)

timing of the interval starts again (resets)

length of interval increases gradually until…

• behaviour occurs very rarely or not at all

• a min amount of reinforcement is given

differential reinforcement of incompatible responding (DRI)

similar to DRO, but reinforces a behaviour that can occur at the same time as a problem behaviour

example of a DRI

biting fingernails → keeping hands below shoulders

differential reinforcement of alternate behaviour (DRA)

extinction of an unwanted behaviour (by reinforcing wanted)